The build instructions are not that interesting, it's a toss-up
between CC0 and BSD-2, but because other CMake bits are BSD-2-Clause,
apply that to more CMakeLists. The copyright date isn't all that
accurate, but these are just inconsequential files.
While here, tidy up and get rid of some useless intermediates.
- This makes linking easier,
- Adds the right includes (needed on FreeBSD),
- Lets us drop silly GUI setting for non-GUI tests (I think this was
a side-effect of compiling on FreeBSD, where UI would pull in
/usr/local/include).
